Percentage Calculator

About the Percentage Calculator

Percentage Calculator solves all three standard percentage problems: what is X% of Y, X is what % of Y, and X is Y% of what. A quick helper for shopping discounts, exam scores and business metrics.

How to use

1. Pick the calculation type from the three options.
2. Fill in the two known numbers.
3. Press Calculate to see the answer with worked steps.

Benefits & key features

• Three calculation modes cover 99% of day-to-day percentage questions.
• Steps are shown so it's great for learning, not just answers.
• Handles negative numbers and decimals.
• Pairs with the Percentage Increase/Decrease Calculator for richer comparisons.

Pro tip

For tip calculations, use X % of Y with X = 15 or 20 and Y = your bill total. The result is the tip.

Why choose toolsfy for Calculators tools?

A good calculator should give you a defensible number you can paste into a spreadsheet, not a vague range behind a paywall. toolsfy's calculators show every formula, every step and every input so you can trust the result — and cross-check it. Because the math runs in your browser, there is no latency, no rate limit, and no risk of a server returning a cached, stale, or rounded answer.

Common use cases

• Engineering students verifying textbook answers on the bus, without burning mobile data on a heavyweight scientific-calculator app.
• Freelancers converting between units in client briefs — millimetres to inches, pounds to kilograms, US fluid ounces to millilitres — in seconds.
• Shopkeepers calculating the effective percentage change in margins after a supplier price hike, without firing up Excel on a point-of-sale tablet.

Frequently asked questions